Abstract

Rectal biopsy homogenates, faecal samples, and leucocyte rich plasma obtained from 39 patients were inoculated into tissue cultures. A non-transmissible cytopathic effect was observed in cultures inoculated with material from patients with Crohn's disease. In a blind study this cytopathic effect was observed in three specimens from three patients with Crohn's disease, in six specimens from four patients with ulcerative colitis, and six specimens from five patients with upper gastrointestinal disease. The cytopathic effect is unlikely to be associated with the bowel diseases tested. These results are also consistent with the failure of others to isolate a virus by the techniques used. With the limited range of techniques used no evidence was obtained to implicate conventional viruses in the pathogenesis of Crohn's disease.